Vapour-Phase and Solid-Phase Epitaxy of Silicon on Solid-Phase Crystallised Seed Layers for Solar Cells Application

Abstract

Vapour-phase and solid-phase epitaxy are used for thickening of a solid-phase crystallised silicon seed layer on glass. Cross-sectional transmission microscope images confirm that a transfer of crystallographic information has taken place from the seed layer into the epilayers. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy reveal that the density of planar defects (mainly on{111}plains) in the vapour-phase epitaxial sample is much higher than in the solid-phase epitaxial sample. These planar defects can act as recombination centres for free-charge carriers. Consequently, PC1D modelled minority carrier diffusion length in the vapour-phase grown epilayer is 50% shorter than that in the solid-phase grown epilayer. As a result, a solar cell grown by solid-phase epitaxy achieves open circuit voltage of 468 mV, short circuit current of 9.17 mA/cm2, and photovoltaic conversion efficiency at 2.75% which are all higher than those of the solar cell grown by vapour-phase epitaxy on the same seed layer, 400 mV, 7.28 mA/cm2, 1.69%, respectively. It proves that solid-phase epitaxy is more suitable for the solar cell growth on the solid-phase crystallised silicon seed layer than vapour-phase epitaxy.

The effect of rapid thermal annealed seed layer on the epitaxial poly-Si thin film solar cell׳s structure quality and performance

“…This result is consistent with the J sc trend from illuminated J ÀV curve. The improved EQE response by RTA treatment for the seed layer should result from increasing of minority carrier diffusion length [6]. This result is consistent with the improvement of V oc due to the better quality of epi-layer by the RTA treatment for the seed layer.…”

“…These samples were then annealed at 580 1C in the nitrogen purged tube furnace for solid-phase epitaxy (SPE) [6]. SPE grown samples received another RTA processing at 950 1C for 3 min to activate dopants and to reduce the defect density.…”

In-Plane Epitaxial Growth of Silicon Nanowires and Junction Formation on Si(100) Substrates

“…In addition, we also carried out similar experiments on Si(111) substrates but most of the in-plane SiNWs grown there are found as free-roaming ones (not shown here). This is reasonable if one recalls that epitaxy growth of Si on Si(100) is easier than that upon Si(111) interface. − Though epitaxy layer-by-layer growth of Si atoms on a Si(111) facet has been commonly observed in relatively thick VLS-grown SiNWs catalyzed by noble metal particles, , epitaxy growth on Si(111) surface involves essentially a bilayer ledge-flow dynamics, which is energetically less efficient compared to the situation on Si(100) surfaces, where new adatoms can be easily stabilized by bonding two neighboring Si atoms on the lower surface atomic layer leading to an effective epitaxy growth.…”

Thermoelectric performance of Si80Ge20−xSbx based multiphase alloys with inhomogeneous dopant distribution

“…1. These shoulders peaks could be formed in two situations: it is either overlapped peaks from different solid solution phases with varied Si/Ge ratios, or it is due to microtwins and stacking faults [26]. For the samples hot pressed from the 6 h-milled and 16 h-milled powders, diffraction peaks of WSi 2 (at $30.25°, 39.84°and 44.87°) and SiC were detected.…”